Vibration damper



F. R. MCFARLAND VIBRATION DAMPER July 31, 1945.

Filed Nov. 18, 1942 INVENTOR.

'Puentes July 31, 1945 UNITED STATES .PATENT orsics Foi-est n.Merci-lana, Huntington woods, M1011.,

assignor to Packard Motor Car Company, Detroit, Mich., a corporation ofMichigan Application November 1s, 1942, serial No. 466,003

` (ci. 'zc-574) 9 13 Claims.

Thisinvention relates tovibrationdamping devices, and more particularlyto devices for damping vibrations induced in engine crankshafts as 311ersult of periodic torque impulsesy applied ere A n object of theinvention is to provide a vibra'- tion damping device in which dampingfriction is regulated through means of an elastic pressure device.

l further object of the invention is to provide l a compact, simpledamping device in which an inertia member is influenced elastically andfric- 4tionallv to control shaft vibrations occurring at differentspeeds.

A further object of the invention is to provide.' in a vibration dampingdevice, two or more rubber control means of differing characteristics.

Other objects of the invention will appear from the followingdescription taken in connection with the drawing, which forms a part ofthis speclhcation, in which zrequire for their control or elimination agreater amount of friction or the dissipation of a greater amount ofenergy than do the vibrations at the lower speeds. ,l

The present invention contemplates a device in which the frlctionalforce for damping torsional vibration is increased by weight membersresponsive to centrifugal forceV and acting through a wedging devicethat will not bind or stick.

Referring t0 the drawing, IIl represents a bearing carried by a wall Ilof an internal combustion engine. An end portion I2 of crankshaft I3 ismounted in the bearing and a connecting rod I4 is'shown pivoted on theend crank of the crankshaft. `The crankshaft extends in the form of areduced portion I5' which has a gear Iii keyed thereto to drive anengine accessory. A further reduced extension portion I1 of thecrankshaft Fig. 1 is a vertical, longitudinal section through itsnatural frequency. At certain speeds of the shaft, called criticalspeeds, its natural period is equal to the period of impressed torque,or some is formed with it is threaded.

A vibration damping device is mounted on the splined portion il of thecrankshaft and has a carrier consisting of spaced disks 2l and 32 fixedto rotate with the crankshaft. Disk 2l extends as a harige from one endof a sleeve or hub 2t splines 'I8 and the extreme end splined on-theshaft and disk 32 surrounds the shaft at the end of the hub remote fromdisk 2 I. Between this flanged hub end and the gear i6 is a spacer ring22 and a-nut @il on the end of the shaft retains the parts in positionthereon.

An inertia member or flywheel it is journalled .on a bearing ring 2ionthe hub 2li between the anges 2l and 32. This ywheel is connected withthe hub by-an elastic means consisting of a rubber disk 28 between andsurface-bonded to thin metal dish 2B. One of the m'etal disks is securedto the flywheel as by screws 21' and the other is harmonic componentthereof, so that this force -will build up elastic energy in the shaft.Thus, a

condition of resonance is produced and torsional Y vibration of greaterorless severity is the result.

d For the -control of such vibrations, various forms of means haveheretofore been proposed which'depend upon damping or the dissipationfrom the vibrating system of sufficient energy t0 prevent resonantgrowth of the'disturbance. `Such devices usually' operate by frictionand elastic means arranged between an inertia-or` weight member and thecrankshaft. Iii-some cases it `has been found dimcult to provide suchmeans dlpted to satilfctorlly damp all 0! the vibratory periods withinthe engine range, especially since these occur at widely separatedspeeds and -with considerably different intensities. Also, the

vila-stimav occurring at the higher shaft speeds op secured to the hubdange as by bolts 28. This elastic means on one side of the ywheelpermits limited relative rotation ci the hub andflvwheel. Furthercontrol of this relative rotation is provided by a friction means shownin the form of a disk 30 in a recess 29 in the ywheel 23. This disk 30is mounted between and engages the ilywheel and the hub flange 2I.

Pressure transmitting means is provided .to

automatically vary the application of friction ior controlling relativeoscillation or rotatlon'oi the flywheel on the' shaft. Such meansconsists oi' a load or pressure transmitting member, which can bein theform lof a rubber ring II, arranged between and engaging the flywheeland the disk I2. Ring 3| is preferablyformed substantially as aright-angled triangle in cross section. The hypothenuse of the trianglefaces the'fLvwheel which is formed with an adjacent surface Il extendingat a similar angle therewith. The hub 20 spacer 22 are preferably sodimensioned that the disk l2 will hold the rubber ring. under pressureagainst the flywheel and thereby set up an initial frictional engagementof disk 3l with A the hub flange and the flywheel.

The rubber ring 3l. at one side of theflywheel and the elastic connector26. at the other both act elastically to damp crankshaft vibrations.Ordinarily such vibration damping arrangement will be more effective inthe lower crankshaft speeds. Itis proposed to further controlfthedamping .of crankshaft vibration by the use of inertia means, in theform Aof weight members ",Ahaving the pressure transmitting meansarranged between them and the adjacent disk 32 and the flywheel. In thepresent showing. the weight members 40 are segmental in shape and areembedded in the rubber ring 3l and preferably surface-bonded thereto.These weight members are spaced annularly and conform in erom section tothe ring in which they are embedded, but, of course, are of smallerdimensions.

When the damping device is assembled, nut 33 Will hold disk 32 againsthub 2l and the hub against the spacer 22 so that they are all heldstationary in an axial direction.- The arrangement is preferablyr suchthat the rubber ring will be compressed in an axial direction holdingthe disk 2i and the flywheel in pressure. engagement with friction disk29. The rubber ring will be held under sumcient pressure in an axialdirection so that the surfaces thereof engaging the disk 32.

and .the flywheel can not shift relative thereto when there is relativerotation of the'ywheel and the carrier means. The rubber ring 3l and therubber disk 2li provide a pair of rubber means controlling relativerotation of the flywheel and the carrier, and the friction disk 29 isenclosed in the flywheel and carrier structure between such pair ofrubber The segmental inertia members will shift radi ally in the rubberring in relation to the rotative Thus movement of the inertia members inapplying Wedging pressure to control the friction developed in thedamping device will always be responsive to the effect of centrifugalforce.

Although the invention has been described in connection with a specificembodiment, .the principles involved are susceptibleof numerous otherapplications which will readily occur to persons skilled in the art.The, invention is therefore to be limited only as indicated by the scopeof the appended claims.

What is claimed is:

l. A vibration damper for a shaft comprising a pair of spaced disksfixed to the shaft, a flywheel between the disks, friction means betweenone disk and the ywheel, rubber means between and tional to speed, andmeans definitely limiting the relative rotation of the flywheel anddisks.

2. A vibration damper for a shaft comprising a carrier having spaceddisks dxed on the shaft, a flywheel `between. the disks, friction meansbetween one of the disks and a face of the flywheel, a rubber ringengaging the other disk and the adjacent face o t the flywheel, andpressure creating means acting on the rubber-ring to engage the ywheelwith the friction means, the pressure being such lthat the rubber ringwill be distorted but the surfaces of said ring engaging the disk andflywheel will not shift relative thereto.

3. A vibration damper for a shaft comprising a `carrier fixed on theshaft having a pair of spaced radial disks, a flywheel 'journalled onthe carrier, a friction disk between one side of the flywheel and onedisk, a rubber ring engaging the other side of the flywheel and theadjacent disk, said 'ring being formed with an inclined face engagingthe adjacent side face of the flywheel, and a plurality of segmentalinertia members embedded in said ring, said members being similar to thering in cross sectional shape and acting to distort the ring in responseto centrifugal force to vary the engaging pressure of the flywheelagainst the friction disk in accordance with the speed of shaftrotation.

4. A vibration damper for a shaft comprising a member fixed to rotatewith the shaft, a flywheel journalled coaxialLv with the shaft, frictionmeans between the member and the flywheel, a rubber ring secured incompression against the flywheel to engage the friction means with themember and the flywheel, and' segmental weight members embedded intherubber ring, said members shifting their position in the ring inresponse to shaft speed to vary the pressure engagement of the frictionmeans with the flywheel and the member.

5. A vibration damper for a shaft comprising a carrier xed to the shaft,a flywheel journalled on the carrier, friction means acting to retardrelativerotation of said flywheel and carrier, a rubber pressure ringengaging the flywheel with the friction means with such pressure that inthe operation'of the damper the surfaces of the rubber ring cannot shiftrelative to the ywheel and carrier and means shiftable in the ring inresponse to centrifugal force to vary the pressure exerted therebyagainst the flywheel.

6. A' vibration damper for shafts comprising a hub member, an inertiamember, friction means between said members retarding the rotation ofone relative to the other, and rubber means at each side of and closingaccess to said friction means and tending to control the operatingdeengaging the other disk and the adjacent portion v of the flywheel,inertia means acting against the rubber means to vary the pressurerelation of gree thereof.

-7. A vibration damper for shafts comprising a hub member, an inertiamember, friction means between said members retarding the rotation ofone relative to the other, rubber means at each side of and closingaccess to said friction means and tending to control the operatingdegree thereof, and means controlling the action of said rubber means bycentrifugal force.

. A vibration damper for shafts comprising hub means, inertia means,friction means between ing to control the operating degree thereof, one.

of said rubber means being secured to the hub the flywheel against thefriction means propor- 7g means and inertia means respectively. theother aecomo of said rubber-means being controlled in its sction bycentrifueai force.

9. A vibration damper foral shaft comprising a hub having a disk. aflywheel mounted adjacentV said disk, friction means between said diskand said flywheel, and rubber means between said hub and saidywheel-eifectina pressure on the friction means and denniteiy limitingrelative rotatijon between the hub .and the ilywheel.

10. A vibrationl damper for a shaft comprising a hub havinga disk, anywheel mounted adiacent said-diskJrlction means between said disk andsaid flywheel, rubberv means between said hub and said flywheel esctinxpressure on the .friction means and deiinltely limiting relativerotation between the hub and the flywheel. and inertia means actin:against a portion of the rubber means to vary tile pressure of thefriction means proportional to speed.

11. A vibration ldamper for "shafts comprising a hub member, an inertiamember, friction means vbetweensaidmembersretariiinxtherotation'ofonerelative to the other. andrubber means directly contacting said huband flywheel and arranged on both sides of said friction means tendingto control the operating degree of saidv friction means.

12. A vibration damper for shafts comprising side of said frictionvmeans tending to control the operating degree thereof, said rubbermeanscombining with the hub and inertia members to enclosethe friction means,and centrifugaliy operating means controlling the action of said rub bermeans; FDREST R. McFARLAND,

